Hot-air furnace.



J. M. BLA-SHFIELD.

.HOT -AIB FURNACE.

APPLICATION FILED MAR. 28, 1914.

Patented Jan. 19, 191

BSHEETS-SHEET 1.

"IE NORRIS PE TERS Co.. PHOTO LITHO. VIASHINb r0. 0 C.

J. M. BLASHFIELD.

HOT AIR FURNACE.

APPLICATION FILED MAB. 28,1914.

1,125,449,, Patented Jan. 19, 1915.

3 SHEETS-SHEET 2.

WM/names THE NORRIS PETERS 60., PHOTG-LITHO WASHINGTON. D. c.

J. M. BLASHP'IELD.

HOT AIR FURNACE.

APPLIOATION FILED MAR. 23, 1914.

Patented Jan. 19, 1915. 3 SHEETS-SHEET 3.

THE NORRIS PETERS 60.. FHOTO-LITHO.. WASHINGTON. D. C.

CJI

prrnn STATES PATENT OFFICE.

JAMES M. BLASHFIELID, OF JACKSON, MICHIGAN, ASSIGNOR OF ONE-HALF 'IO THEOPI-IILUS SCOTT, OF JACKSON, MICHIGAN.

HOT-AIR FURNACE.

Specification of Letters Patent.

Patented Jan. 19, 1915.

Application filed March 28, 1914. Serial No. 827,934.

To all whomit may concern:

Be it known that I, JAMES M. BLASHFIELD, citizen of the United States, residing at Jackson, in the county of Jackson and State of Michigan, have invented certain new and useful Improvements in Hot-Air Furnaces, of which the following is a specification.

My invention relates to furnaces, and particularly to furnaces adapted for heating buildings.

The invention has relation to the type of hot air furnaces comprising an inner flue, an outer wall forming a space between the inner flue and wall and means for controlling the passage of air through such space for regulating the burning of the fuel.

The invention has for its object to devise a heating furnace of the type hereinbefore stated embodying a novel structural arrangement and to minimize the number of joints as well as to provide an arrangement which admits of the parts being easily and quickly assembled and retained in the required position without necessitating the use of fastening means.

A further purpose of the invention is the provision of a hot air furnace embodying a maximum amount of heating surface, there by economizing in the consumption of fuel and insuring a rapid heating of the air passing through the furnace on its way to the apartments or places to be heated.

The invention consists of the novel features, details of construction and combinations of parts which hereinafter will be more particularlv set forth, illustrated in the drawings and pointed out in the appended claims.

My invention is illustrated in the accompanying drawings wherein:

Figure l'is a perspective view of a furnace constructed in accordance with my invention. Fig. 2 is a diametrical section through the furnace on the line 22 of Fig.

3. Fig. 3 is a transverse section on the line 33 of Fig. 2. Fig. 4 is a fragmentary section on the line 41 of Fig. 2. Fig. 5 is a top plan view of the oscillating grate. Fig.

Referring to these drawings, it will be seen that my improved furnace comprises an outer casing 2 which is preferably of sheet metal. Disposed centrally within this outer casing is a vertical air flue or chamber 3 which extends nearly up to the top of the casing but discharges into a distributing air chamber 4. The upper and lower ends of this central air flue are open and the lower end of the air flue 3 opens into a receiving air chamber 5 disposed in the floor of the basement in which the heating furnace is located. This receiving air chamber 5 is of course connected to any suitable source of air, as for instance the air exterior to the building.

' Disposed concentrically to the wall 6 of the air chamber 3 and spaced therefrom is the wall 7 which surrounds the ash-pit 8, the fire-pot 9 and the smoke chamber 10. Preferably this wall 7 is formed of cast sections. The lower end of the ash-pit space 8 is closed by the inwardly turned flange 11 of the wall 7, the wall 6 of the central air flue 3 being provided with an annular shoulder 12 which rests upon the fiangell. The

ash-pit 8 is separated from the fire-pot 9 by a grate. This grate is annular in form and comprises the oscillatable section 13 and the relatively fixed section l i'whose construction will be later described.

The upper end of the annular fire-pot 9 is separated from the smoke chamber 10 by a septum 15 formed adjacent the central fine 6 with a plurality of openings 16. This septum 15 at its inner edge rests upon an annular shoulder 17 formed upon the wall of theair flue 3 and at its outer edge is flanged and bolted to the upper end of the wall 7 as at 18. The upper end of the space between the wall 7 and the wall 6 is closed by an annular upwardly bowed casting 19, the inner and outer edges of which are rabbeted to engage over the upper ends of the walls 6 and 7. This cap or casting 19 prevents the passage of products of combustion from the combustion chamber into the air distributing chamber 4. A deflector 20 is disposed above the upper end of the air flue 3 in spaced relation to the upper end of the wall 6. This deflector as illustrated is concavo-conveX, the convex side of the deflector being downward and is supported upona plurality of legs 21, these legs being outwardly and downwardly extended and bolted or otherwise attached to the casting 19. -Tliis deflector acts to impede the too rapid passage of the -air through the air chamber 3 and distributes the air evenly in the distributing air chamber 4.

. A thirnble enters the wall 2 at the back of-the furnace and extends through the air whereby access may be had to-the smoke chamber 10. e j i Extending from the upper end, ofthe ashpitfl just above the grate support and disposed in the airspace between the wall 2and the wall. Tis. a dust flue 26. Thelower end of this dust flue is connected to the ash-pit space; by anelbow 27. The upper end of the fiueislconnected with the thimble 24 by the downwardly turned flange 28,. A damper .29 is disposed inthis flue 26, the damper being controlled by means ,ofa spindle. 30 projecting to the front of the furnace. c j l The grate as b fore stated consists of two sections, one fixed andone oscillating. The fixedsection of the grate which is designated-14 is formed in two sections and is annular in form... At its inner edge this fixedsection is formed with'a flange 31 which restsupon an annular shoulder32 formed upon the wall 6. Ashoulder 33 also formed upon the wall 6 in spaced relation totheshoulder32 bears upon the upper face "of theinner margin of the fixed section 14. The outer. margin of the fixed grate sec tion is held to the wall, 2 by bolts 34 in the L45 imanner shown clearly in .Fig. 2.

' @Disposed just below the fixed section 14 is the ,oscillatable section 13 which-rests upon its inner margin upon a shoulder 35 formed upon the wall 6. and at its outer margin ,restsupon av ring 36 bolted to the wall 7. The .oscillatable section 13 vas illustrated in Figs-3,4 and 5, comprises a plateformed "in two sections, these sections, being designated respectively 13 and. 13 and this plate is. provided with a plurality of radially disposed slots 37. The sections 13 and 13 are held to each other by bolts 38 which pass through downwardly extending facing lugs or flanges 39 formed upon the under faces ofthesections 13 and 13 I The; oscillatable grate 13 is formed with a socket 40 which projects out through a slot '41lformed in the wall 7 as shown clearly in Fig.4and is adapted toreceive a handle 42 which extends to the exterior of the furnace.

The 5101: 41 is closed by a shield43 which is attached .to the .socket 40. and which is of .such length that thelever 42 may be oscillated to the full extent on the slot 41 with- 4 out the slot 41 being at any time uncovered.

The fixed section 14 as shown in Fig 3 consists of anannular plate formed with. ra-

diating arms 44, these arms defining relatively large openings 45 between the arms.

There are relatively few of these arms in comparison with the number of slots in the oscillating plate 13. i Y

The operation'of this grateis as follows. Upon an oscillation of the handle 42, the grate section 13 will be oscillated and the coal which is supported upon the grate section 13 as this grate section is oscillated, will ride over the arms 44 so that the arms will tend to shift the coal and distribute it uponthe upper face of the'gra'te section nace with coal, I provide two coal chutes 46 disposed; on the same'level anaextendin approximately tangential to the axial center of the grate surface. Inoth'erwords, the adjacent walls of the twocoal chutes ex tend approximately radially while the outer walls extend tangentially, Thus the coal chutes are relatively wide andp'ermit coal to be thrown into the fire box and tobe dis charged entirely around the grate surface even to a point behindthe central flue. It

will be obvious that if onlyone coal chute is providechdisposed in theordinary" position in front of the furnace andextending radially tothe axisof the furnace, the coal could not bereadily distributed upon the annular grate. With this arrangement, however, l dispose the openings of the coal chutes at the most convenientpoint, that is, both at thefront of the furnace, and yet am able to secure a proper distribution of the coal upon the grate. This proper distribution of coal is, of course, aided by the curvature ofthe wall 7 which tends to deflect coal thrown into the chutes 46 around to the backportion ofthegrate. I ialsop'rovide a,pair.,of ash pit chutes 48? opening from the front of the furnace into the ashpit 8, and likewise located each at a tangent tothe axial center of the furnace, theseashpit chutes being located in alinement with the chutes 46 and extending inward from the front of the furnace tothe ash-pit 8. The chutes 46 are closed by doors 47 of any suitable character and shown as hinged doors. It'will be noted that the outer ends of the chutes 46 are flush with the exterior .wall of the furnace and that the doors 47 are slightly curved to'suit the curvature of the exterior wall of the furnace. The ashpit chutes e8 are also normally closed by means of doors edhaving the same form as the doors 47.

One of the ash-pit doors is shown provided with a draft opening which is controlled by meansof a damper door 4L9 of any usual type. Obviously, each of the ashpit doors maybe provided with a damper controlled opening if desired.

From the distributing air chamber 4., the hot air flues or pipes lead as is usual to various portionsof the building. Thereceiving air chamber 5 of course opens into the central air pipe or chamber 3 and into the air chamber formed between the outer wall 2 and the intermediate wall 7 Thus air entering the receiving air. chamber passes up around the exterior of the firepot and also passes up through the central air chamber 3, this air being discharged into the air distributing chamber 4: and from thence passing to the pipes 50.

The operation of my furnace will be plainly evident from what has gone before. Goal is of course delivered through the coal chutes onto the grate. All airwhich passes through the furnace enters initially into the receiving air chamber and passes up through the central air flue or chamber, or the air chamber formed between the outer wall 2 and the fire-pot. Thus practically all air is subjected to the action of the fire, and the air which passes up through the central air flue 3 is subjected to the action of the hottest portion of the fire. The air which passes up through the chamber 3 is distributed uniformly into the distributing air chamber by means'of the deflector 20 which acts to impede the'too rapid upward passage of the air in chamber 3 so that it will be subjected to the action of the fire for a longer period. The heated products of combustion are impeded in their upward passage by the septum 15 but eventually pass into the smoke chamber 10 and thence out through the smoke flue. If it is desired to reduce the draft through the fire pot, the damper 29 may be opened which will cause a large portion of the air entering theashpit to pass directly up through the flue 26 into the smoke chamber 10 and thence out through the flue 22. Vfhen the damper 29 is closed, it will be evident that all air entering the ash-pit will pass upward through the grates l3 and 14;.

simple in construction and therefore may be cheaply made and readily set up. The grate thoroughly distributes the coal and therefore makes a uniform fire so as to secure a maximum heating action of the coal. Inasmuch as the air is so thoroughly subjected to the action of the fire, I secure a maximum of efficiency from a minimum amount of fuel.

It will be seen that the outer casing 2, the base section ofthe wall 7 and the lower end of the wall 6 all seat upon a base ring 51' which is formed to receive and support the lower ends of these members. It will further be seen that the lowerend of the wall 6 extends into a central opening formed in the flange 11, theshoulder 12 resting upon a margin of this opening. The assembling of the furnace is therefore very simple and the parts may be readily cast and put together.

Having thus described theinventiomwhat is claimed as new is:

1. In a heating furnace, comprising an annular fire-pot and a surrounding air chamber, two fuel charging chutes extendingacross the air chamber at the same level and opening through the outer wal of the furnaceupon the same side to admit of supplying fuel to the furnace from the front through either chute, one of the walls of the chutes being tangential to the curved wall of the fire-pot to admit of such curved wall deflecting the fuel.

2. In a heating furnace, comprising an annular fire-pot, a surrounding air chamher and a centrally disposed air flue, two fuel charging chutes extending across the air chamber at the same level and opening through the outer wall of the furnace upon the same side, one of the walls of the chutes being tangential to the curved Wall of the fire-pot to admit of such curved wall directing the fuel to the rear of the central air flue.

3. In a heating furnace comprising an annular fire-pot and ash-pit, separated by .a fuel grate, an air chamber surrounding the fire-pot and ash-pit, and a centrally disposed air flue extending through the ash-pit and fire-pot, two fuel charging chutes arranged at the same level and extending across the air chamber and opening through the outer wall of the furnace on the same side, and two ash chutes in vertical line with the two fuel chutes one of the walls of the two sets of chutes being tangential to the curved walls of the fire-pot and ash-pit, respectively.

4:. In a heating furnace, an annular wall having an inturned flange at its lower end, an airflue supported at its lower end upon the inturned flange and extending vertically and formed with spaced outer shoulders, an annular grate supported at its inner edge 'upon one of theshoulders and held upon" such shoulder by the shoulder next above, a

rest upon the wall supporting the grate at its outer edge, andmeans spanning the space formed between the air flue and annular -;wall and secured thereto and in contact with the grateto hold the same against vertical movement,

5. In a heating furnace, an'outer annular wall having an inner flange at its lower end, a-vertical air flue supported upon the inner flange, an annular grate arranged between {the flue and annular wall and supported thereby, a septum extending across the space between theflue and annular wall near the upper ends thereof, anannular cap closing the said space and closely fitted to the upper ends of the flue and annular wall, said cap being arched between its inner and outer edges, and a deflector supported on the cap and spaced therefrom and extending'over the air flue.

6. A heating furnace comprising a basering, an annular wall having an inturned flangeat its lower end in the plane of the base-ring and supported thereon, a centrally disposed air flue supported at its lower end upon the inturned flange of the annular wall, a fuel grate supported the annularspace formed between the air flue and wall,

the space above the grate forming an anr nular combustion chamber and the space below the grate forming an annular ash pit, a

septum extending across the upper portion of the annular's'paceformed between the air flue and wall, and having a smoke chamber above, an annular cap closing the annular space and supported upon the upper ends ofthe air flue and annular Wall, a deflector supported upon'the capland spaced therefrom and extending over the upper end of the air flue, a casing incloslng the annular wall and spaced therefrom and supported upon the base ring, said casing projecting above the cap and closed at its upper end to form a distributing air chamber, thimbles extending across the space formed between the casing and annular wall and making close connection therewith, one of i such thimbles constitutes a smoke outlet and Copies of this patent may be obtained for five cents each, by'addressing' the Commissioner of Patents,

' Washington, I). G. I 

